The project will examine cigarette smoking behaviorally, using the methods of operant conditioning. An apparatus has been developed that permits almost natural cigarette smoking by volunteer subjects under laboratory conditions, while data on the constituents of smoking behavior -- i.e., lighting up, puffing, and extinguishing a cigarette -- are automatically recorded and stored in a computer. Any or all aspects of smoking can be made contingent on an arbitrary instrumental response, using any schedule of reinforcement. The research will provide, first, fine-scale data on smoking by a sample of volunteer subjects. Next, it will examine if, and how, smoking displays the quantitative properties of reinforced behavior. The research should permit numerical assessments of the reinforcing power, or "value" in the economic sense, of smoking for individual subjects. The primary long-term objective is to gain knowledge applicable to techniques of control, including self-control, over smoking.